User Interface: Store Front
This is what your customers will see at the final stage of the checkout if they do not have any associated tokens. In the example here we are running the extension in test mode which is why the yellow notification is showing up.

On the other hand, if a customer has already made a checkout with a valid credit card and you have enabled Tokenization from the admin panel, their token will be saved for later use. This is what they will see on their second and subsequent checkouts:

Upon order confirmation the order will be directly finished because the payment details are already stored in Mastercard.